Philips 17PF7835, 15LCD35 Schematic

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IMPORTANT SAFETY NOTICE

Proper service and repair is important to the safe, reliable operation of all Philips Consumer Electronics Company** Equipment. The service procedures recommended by Philips and described in this service manual are effective methods of performing service operations. Some of these service operations require the use of tools specially designed for the purpose. The special tools should be used when and as recommended.

It is important to note that this manual contains various CAUTIONS and NOTICES which should be carefully read in order to minimize the risk of personal injury to service personnel. The possibility exists that improper service methods may damage the equipment. It also is important to understand that these CAUTIONS and NOTICES ARE NOT EXHAUSTIVE. Philips could not possibly know, evaluate and advise the service trade of all conceivable ways in which service might be done, or of the possible hazardous consequences of each way. Consequently, Philips has not undertaken any such broad evaluation. Accordingly, a servicer who uses a service procedure or tool which is not recommended by Philips must first satisfy himself thoroughly that neither his safety nor the safe operation of the equipment will be jeopardized by the service method selected.

** Hereafter throughout this manual, Philips Consumer Electronics Company will be referred to as Philips.

WARNING

Critical components having special safety characteristics are identified with a or "S" by the Ref. No. in the parts list and enclosed within a broken line* (where several critical components are grouped in one area) along with the safety symbol

on the schematics or exploded views. Use of substitute replacement parts which do not have the same specified safety characteristics may create shock, fire, or other hazards. Under no circumstances should the original design be modified or altered without written permission from Philips. Philips assumes no liability, express or implied, arising out of any unauthorized modification of design. Servicer assumes all liability.

* Broken Line ____ _ ____ _ ____ _ ____

FIRE AND SHOCK HAZARD

1.Be sure all components are positioned in such a way as to avoid the possibility of adjacent component shorts. This is especially important on those chassis which are transported to and from the service shop.

2.Never release a repaired unit unless all protective devices such as insulators, barriers, covers, strain reliefs, and other hardware have been installed in accordance with the original design.

3.Soldering and wiring must be inspected to locate possible cold solder joints, solder splashes, sharp solder points, frayed leads, pinched leads, or damaged insulation (including the ac cord). Be certain to remove loose solder balls and all other loose foreign particles.

4.Check across-the-line components and other components for physical evidence of damage or deterioration and replace if necessary. Follow original layout, lead length, and dress.

5.No lead or component should touch a receiving tube or a resistor rated at 1 watt or more. Lead tension around protruding metal surfaces or edges must be avoided.

6.Critical components having special safety characteristics are identified with an 'S' by the Ref. No. in the

parts list and enclosed within a broken line* (where several critical components are grouped in one area) along with the safety symbol on the schematic diagrams and /or exploded views.

7.When servicing any unit, always use a separate isolation transformer for the chassis. Failure to use a separate isolation transformer may expose you to possible shock hazard, and may cause damage to servicing instruments.

8.Many electronic products use a polarized ac line cord (one wide pin on the plug). Defeating this safety feature may create a potential hazard to the servicer and the user. Extension cords which do not incorporate the polarizing feature should never be used.

9.After reassembly of the unit, always perform an ac leakage test or resistance test from the line cord to all exposed metal parts of the cabinet. Also, check all metal control shafts (with knobs removed), antenna terminals, handles, screws, etc., to be sure the unit may be safely operated without danger of electrical shock.

* Broken line ____ _ ____ _ ____ _ ____

LEAKAGE CURRENT COLD CHECK

1.Unplug the ac line cord and connect a jumper between the two prongs of the plug.

2.Turn on the power switch.

3.Measure the resistance value between the jumpered ac plug and all exposed cabinet parts of the receiver, such as screw heads, antennas, and control shafts. When the exposed metallic part has a return path to the chassis, the reading should be between 1 megohm and 5.2 megohms. When the exposed metal does not have a return path to the chassis, the reading must be infinity. Remove the jumper from the ac line cord.

LEAKAGE CURRENT HOT CHECK

1.Do not use an isolation transformer for this test. Plug the completely reassembled receiver directly into the ac outlet.

2.Connect a 1.5k, 10W resistor paralleled by a 0.15uF. capacitor between each exposed metallic cabinet part and a good earth ground such as a water pipe, as shown below.

3.Use an ac voltmeter with at least 5000 ohms/volt sensitivity to measure the potential across the resistor.

4.The potential at any point should not exceed 0.75 volts. A leakage current tester may be used to make this test; leakage current must not exceed 0.5mA. If a measurement is outside of the specified limits, there is a possibility of shock hazard. The receiver should be repaired and rechecked before returning it to the customer.

5.Repeat the above procedure with the ac plug reversed. (Note: An ac adapter is necessary when a polarized plug is used. Do not defeat the polarizing feature of the plug.)

With the instrument completely reassembled, plug the ac line cord directly into a 120Vac outlet. (Do not use an isolation transformer during this test.) Use a leakage current tester or a metering system that complies with American National Standards Institute (ANSI) C101.1 Leakage Current for Appliances and Underwriters Laboratories (UL) 1410, (50.7). With the instrument ac switch first in the on position and then in the off position, measure from a known earth ground (metal water pipe, conduit, etc.) to all exposed metal parts of the instrument (antennas, handle brackets, metal cabinet, screw heads, metallic overlays, control shafts, etc.), especially any exposed metal parts that offer an electrical return path to the chassis. Any current measured must not exceed 0.5mA. Reverse the instrument power cord plug in the outlet and repeat the test. See the graphic below.

TV SAFETY NOTES

SAFETY CHECKS

After the original service problem has been corrected, a complete safety check should be made. Be sure to check over the entire set, not just the areas where you have worked. Some previous servicer may have left an unsafe condition, which could be unknowingly passed on to your customer. Be sure to check all of the following:

Fire and Shock Hazard

Implosion

X-Radiation

Leakage Current Cold Check

Leakage Current Hot Check

Picture Tube Replacement

Parts Replacement

WARNING: Before removing the CRT anode cap, turn the unit OFF and short the HIGH VOLTAGE to the CRT DAG ground.

SERVICE NOTE: The CRT DAG is not at chassis ground.

IMPLOSION

1.All picture tubes used in current model receivers are equipped with an integral implosion system. Care should always be used, and safety glasses worn, whenever handling any picture tube. Avoid scratching or otherwise damaging the picture tube during installation.

2.Use only replacement tubes specified by the manufacturer.

X-RADIATION

1.Be sure procedures and instructions to all your service personnel cover the subject of X-radiation. Potential sources of X-rays in TV receivers are the picture tube and the high voltage circuits. The basic precaution which must be exercised is to keep the high voltage at the factory recommended level.

2.To avoid possible exposure to X-radiation and electrical shock, only the manufacturer's specified anode connectors must be used.

3.It is essential that the service technician has an accurate HV meter available at all times. The calibration of this meter should be checked periodically against a reference standard.

4.When the HV circuitry is operating properly there is no possibility of an X-radiation problem. High voltage should always be kept at the manufacturer's rated value - no higher - for optimum performance. Every time a color set is serviced, the brightness should be run up and down while monitoring the HV with a meter to be certain that the HV is regulated correctly and does not exceed the specified value. We suggest that you and your technicians review test procedures so that HV and HV regulation are always checked as a standard servicing procedure, and the reason for this prudent routine is clearly understood by everyone. It is important to use an accurate and reliable HV meter. It is recommended that the HV reading be recorded on each customer's invoice, which will demonstrate a proper concern for the customer's safety.

5.When troubleshooting and making test measurements in a receiver with a problem of excessive high voltage, reduce the line voltage by means of a Variac to bring the HV into acceptable limits while troubleshooting. Do not operate the chassis longer than necessary to locate the cause of the excessive HV.

6.New picture tubes are specifically designed to withstand higher operating voltages without creating undesirable X-radiation. It is strongly recommended that any shop test fixture which is to be used with the new higher voltage chassis be equipped with one of the new type tubes designed for this service. Addition of a permanently connected HV meter to the shop test fixture is advisable. The CRT types used in these new sets should never be replaced with any other types, as this may result in excessive X-radiation.

7.It is essential to use the specified picture tube to avoid a possible X-radiation problem.

8.Most TV receivers contain some type of emergency "Hold Down" circuit to prevent HV from rising to excessive levels in the presence of a failure mode. These various circuits should be understood by all technicians servicing them, especially since many hold down circuits are inoperative as long as the receiver performs normally.

PICTURE TUBE REPLACEMENT

The primary source of X-radiation in this television receiver is the picture tube. The picture tube utilized in this chassis is specially constructed to limit X-radiation emissions. For continued X- radiation protection, the replacement tube must be the same type as the original, including suffix letter, or a Philips approved type.

PARTS REPLACEMENT

Many electrical and mechanical parts in Philips television sets have special safety related characteristics. These characteristics are often not evident from visual inspection nor can the protection afforded by them necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. The use of a substitute part which does not have the same safety characteristics as the Philips recommended replacement part shown in this service manual may create shock, fire, or other hazards.

PRODUCT SAFETY GUIDELINES FOR ALL PRODUCTS

CAUTION: Do not modify any circuit. Service work should be performed only after you are thoroughly familiar with all of the following safety checks. Risk of potential hazards and injury to the user increases if safety checks are not adhered to.

USE A SEPARATE ISOLATION TRANSFORMER FOR THIS UNIT WHEN SERVICING.

PREVENTION OF ELECTROSTATIC DISCHARGE (ESD)

Some semiconductor solid state devices can be damaged easily by static electricity. Such components commonly are called Electrostatically Sensitive (ES) Devices, Examples of typical ES devices are integrated circuits and some field-effect transistors and semiconductor "chip" components. The following techniques should be used to help reduce the incidence of component damage caused by electrostatic discharge (ESD).

1.Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off any ESD on your body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging ESD wrist strap, which should be removed for potential shock reasons prior to applying power to the unit under test.

2.After removing an electrical assembly equipped with ES devices, place the assembly on a conductive surface such as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.

3.Use only a grounded-tip soldering iron to solder or unsolder ES devices.

4.Use only an anti-static solder removal device. Some solder removal devices not classified as "antistatic (ESD protected)" can generate an electrical charge sufficient to damage ES devices.

5.Do not use Freon propelled chemicals. These can generate electrical charges sufficient to damage ES devices.

6.Do not remove a replacement ES device from its protective package until immediately before you are ready to install it (most replacement ES devices are packaged with leads electrically shorted together by conductive foam, aluminum foil or comparable conductive material).

7.Immediately before removing the protective material from the leads of a replacement ES device, touch the protective material to the chassis or circuit assembly into which the device will be installed.

CAUTION: Be sure no power is applied to the chassis or circuit and observe all other safety precautions.

8.Minimize bodily motions when handling unpackaged replacement ES devices. (Otherwise harmless motion such as the brushing together of your clothes fabric or the lifting of your feet from a carpeted floor can generate static electricity (ESD) sufficient to damage an ES device.)

NOTE to CATV system Installer:

This reminder is provided to call the CATV system installer's attention to article 820-22 of the NEC that provides guidelines for proper grounding and, in particular, specifies that the cable ground shall be connected to the grounding system of the building, as close to the point of cable entry as practical.

PRACTICAL SERVICE PRECAUTIONS

IT MAKES SENSE TO AVOID EXPOSURE TO ELECTRICAL SHOCK. While some sources are expected to have a possible dangerous impact, others of quite high potential are of limited current and are sometimes held in less regard.

ALWAYS RESPECT VOLTAGES. While some may not be dangerous in themselves, they can cause unexpected reactions – reactions that are best avoided. Before reaching into the powered color TV set, it is best to test the high voltage insulation. It is easy to do, and is just a good service precaution.

BEFORE POWERING UP THE TV WITH THE BACK OFF (or on a test fixture), attach a clip lead to the CRT DAG ground and to a screwdriver blade that has a well insulated handle. After the TV is powered on and high voltage has developed, probe the anode lead with the blade, starting at the bottom of the High Voltage Transformer (flyback – IFT). Move the blade to within two inches of the connector of the CRT. IF THERE IS AN ARC, YOU FOUND IT THE EASY WAY, WITHOUT GETTING A SHOCK! If there is an arc to the screwdriver blade, replace the High Voltage Transformer or the lead, (if removable) whichever is causing the problem.

PICTURE TUBE REPLACEMENT PROCEDURE

Note: a. Two (2) people are required to handle this picture tube.

b.Safety Glasses must be worn during this procedure or whenever directly handling a picture tube.

c.Take care in each step not to damage the CRT or the cabinet.

1.Remove the Chassis and the CRT Socket Board Module from the cabinet.

2.A furniture pad or blanket should be positioned on the floor to support only the CRT Face. This pad or blanket should be high enough to keep the CRT Face approximately 12 to 14 inches off the floor.

3.Using two people, place the cabinet in a front down position with the CRT Face on the pad or blanket.

4.Place padded blocks under each corner of the cabinet to keep it from rocking.

5.Remove the four screws, at the corners of the CRT.

6.With two people lowering the cabinet to the floor, leave the CRT elevated by the pad or blanket.

Note: Take care not to grasp the neck of the CRT during this procedure, as it is extremely fragile.

7.Two (2) people may then lift the CRT from the cabinet.

8.Remove the degaussing coil from the defective CRT and mount on the replacement. Take care to maintain the exact shape and fit.

To install the new CRT, reverse steps 1 to 7.

GENERAL INFORMATION

Manual 7631, Model 15PF992517

Introduction:

Available in the first quarter of 2002, the 15PF9925 is a 15 inch LCD TV/Monitor.

The technology involved is advanced and highly integrated, dedicated electronics are present. The set consists of the assemblies:

∙LCD panel

∙Main Chassis panel

∙Control panel

∙Tuner Pack

The LCD panel is a non-repairable assembly. Defective LCD panels will be returned to the supplier. Main Chassis, Control and Tuner Pack are panels that can be repaired down to component level.

LCD TV/Monitor

Features:

∙TFT LCD 1024x768 pixels

∙brightness: 400cd/m2

∙contrast ratio: 300:1

∙de-interlacing

∙comb filter

∙integrated TV tuner

∙100 presets

∙stereo (2-carrier + NICAM)

∙TOP/FLOF teletext (8-p. memory)

∙integrated sound system

∙2x1 Watt RMS

∙graphic equalizer

∙Euro-A/V / SCART

∙cvbs-in

∙Y/C-in

∙headphones out

∙PC-in (up to XGA 1024x768/85Hz)

∙ARCH table-top stand incl.

∙optional wall-bracket

ADJUSTMENTS & TROUBLESHOOTING

- Model 15PF99, Manual 7631

Notes:

(1)This set uses an adapter, so connect the adapter and the set correctly before adjustment.

(2)The adjustment must be performed under the correct sequence.

(3)The adjustment must be performed in the circumstance of 25°+/-5C of temperature and 65+/-10% of relative humidity if there is no specific designation.

(4)The input voltage of the receiver must keep 100~220V, 50/60Hz in adjusting.

(5)The set must be operated for 30 minutes preliminarily before adjustment if there is no specific designation.

*“Heat Run” must be performed with the full white signal or TV noise signal in the internal part of the set.

*The time for “Heat Run” can be changed owing to production plan.

PC Input Mode Adjustment

Required Test Equipment

(1)A pattern generator being in proportion to VG819; Pattern of 64 tones

(2)A remote control

Preparation for Adjustment

(1)Perform “Heat Run” for more than 30 minutes in white pattern.

(2)Connect the signal of pattern generator with LCD TV.

(3)Lean the set 45° backward. (Adjustment is easy.)

(4) Set the PC mode menu as below.

	Contrast	Brightness
Initial Value	70	100

White Adjustment

(1)Approve the signal of 64 tones of XGA (1024 * 768).

(2)Select all the gain of R, B and G with using ADJ of remote control.

(3)After making 62 tones, 63 tones and 64 tones not distinguished with using each signal of R, G and B, finish adjusting at the moment when the signal 62, 63 and 64 is distinguished.

	R	G	B	Error
Color Coordinates (x, y)	0.63 0.34	0.30 0.60	0.14 0.10	+/- 0.03
AD9884	0x02	0x03	0x04	Register

Position of Mode Adjustment

Mode	VGA-60	VGA-67	VGA-72	VGA-75	VGA-85	TEXT-70	SVGA-56	SVGA-60	SVGA-72
H_Total	800	864	832	840	832	900	1024	1056	1040
H_Display	640	640	656	640	640	720	800	800	800
H_Blanking	160	224	176	200	192	180	224	256	240
H_Sync	96	64	40	64	56	108	72	128	120
H Polarity	NEG.	NEG.	NEG.	NEG.	NEG.	NEG.	POS	POS	POS
H_Bp	48	96	120	120	80	54	128	88	64
H_Fp	16	64	16	16	56	18	24	40	56
H-Freq[KHz]	31.469	35.0	37.861	37.5	43.269	31.469	35.156	37.879	48.077
/Clk[MHz]	25.175	30.24	31.5	31.5	36.0	28.324	36.0	40.0	50.0
V_Total	525	525	520	500	509	449	625	628	666
V_Display	480	480	496	480	480	400	600	600	600
V_Blanking	45	45	24	20	29	49	25	28	66
V_Sync	2	3	3	3	3	2	2	4	6
V Polarity	NEG	NEG	NEG	NEG	NEG	POS	POS	POS	POS
V_Bp	33	39	20	16	25	34	22	23	23
V_Fp	10	3	1	1	1	13	1	1	37

Mode	SVGA-75	SVGA-85	XGA-60	XGA-70	XGA-75	MAC-75	XGA-85	VGA-70
H_Total	1056	1048	1344	1328	1312	1152	1376	800
H_Display	800	800	1024	1024	1024	832	1024	640
H_Blanking	256	248	320	304	288	320	352	160
H_Sync	80	64	136	136	96	64	96	96
H Polarity	POS	POS	NEG	NEG	POS	NEG	POS	POS
H_Bp	160	152	136	144	176	224	208	48
H_Fp	16	32	160	24	16	32	48	16
H-Freq[KHz]	46.875	53.674	48.363	56.476	60.023	49.725	68.677	31.468
/Clk[MHz]	49.5	56.25	65.0	75.0	78.75	57.283	84.997	70.090
V_Total	625	631	806	806	800	667	808	449
V_Display	600	600	768	768	768	624	768	350
V_Blanking	25	31	38	38	32	43	40	99
V_Sync	3	3	6	6	3	3	3	2
V Polarity	POS	POS	NEG	NEG	POS	NEG	POS	NEG
V_Bp	21	27	29	29	28	39	36	35
V_Fp	1	1	3	3	1	1	1	12

TROUBLESHOOTING

General Features

No.	Symptom		Cause		Check Point
1	Soft touch doesn’t		Defective speaker wire		1)	Make some space between the speaker wire and
	function properly		and inverter wire		the Soft touch Board by sticking the speaker wire
					to the guide hole of the cabinet.
					2)	Arrange working state of A1. Tape in the inverter wire
					and correct working state of the Shield case.
2	Soft touch doesn’t		1) Broken components and		1)	Check Soft touch with eyes
	function		soldering of them			Check and repair soldering
			2) P401 connector error		2)	Check and repair the P401 connector
3	No screen		Input error of inverter connector		1)	Bend the pin legs of P801 connector -> recheck them
					2)	Check and repair the IC801, IC802 SI4925


			P502 and Pin 21 connector		1) Check and fix P502 connector
			being slipped out		2)	Check and fix the components at P502 LCD module
						and at main board.




			Cracked components and		1)	Check and repair tuner board and main board
			soldering at tuner board		2)	Solder Q301, Q302, Q402, Q403, Q801 and R802.


4	Dark screen		1) Defective LCD lamp		1)	Replace the inverter
			2) Defective inverter		2)	Replace the LCD lamp
5	Broken OSD display		Defective the font rom of IC505		Replace the font rom of IC505
PC Mode
No.		Symptom		Cause		Check Point
6		Screen noise		Clock or phase being		1) Resetting is needed according to the video card of each
				not able to be adjusted		PC
						2) Adjust auto configure operation.
7		Screen position error		Screen position error		Adjust horizontal and vertical position until the screen
				horizontally or vertically		displays normally
8		Color beat noise		Soldering AD converter		Recheck and repair AD9884
				or making it short
TV and external input
No.		Symptom		Cause			Check Point
9		No sound		Defective Reset IC of IC603			1) Check volume and speaker
		- Speaker		Defective MSP3440 of IC601			- Sound comes out only when being inputted into
		- Earphone					Audio L/R
							2) Check after replacing IC603
							3) Replace IC601
10		Video color beat noise		Earphone shield case being			Check the mould of shield and J403, Replace shield
				touched			case
				Soldering IC301 and IC501			Re-soldering